对地靶射击时飞行安全问题研究

针对目前估算式计算出的退出地靶射击时损失高度比实际小的问题，提出了退出地靶射击损失高度可分三阶段的估算方法，具体计算分析了延迟时间、飞行速度、俯仰角、过载等变化对退出地靶射击损失高度的影响程度，指出俯仰角绝对值大、射击距离近、贪恋观看弹着点、退出时机晚、拉起过载小和拉杆粗猛等是影响地靶射击训练安全的重要因素，明确了退出地靶射击过程正确的驾驶方法，强调了靶场指挥员的重要作用，对提高对靶射击成绩，尤其是保证对地靶射击训练安全有着积极的意义。     

Solar filament eruptions and their physical role in triggering coronal mass ejections

Solar filament eruptions play a crucial role in triggering coronal mass ejections (CMEs). More than 80% of eruptions lead to a CME. This correlation has been studied extensively during the past solar cycles and the last long solar minimum. The statistics made on events occurring during the rising phase of the new solar cycle 24 is in agreement with this finding. Both filaments and CMEs have been related to twisted magnetic fields. Therefore, nearly all the MHD CME models include a twisted flux tube, called a flux rope. Either the flux rope is present long before the eruption, or it is built up by reconnection of a sheared arcade from the beginning of the eruption.     

航空电动机组件失偶角度和失偶时间的测量

介绍了为测量航空电动机组件失偶角度和失偶时间而研制的一种测量装置，该测量装置可与计算机配合使用。它功能齐全、使用方便、造价便宜，完全满足航空电机测量的技术性能指标要求。     

一种测量旋转条件下底排装药燃速的方法

给出了一种利用高速摄影技术测量旋转条件下底排装药燃速的方法，其测量误差小于０．８％，并建立了燃速增大系数与径向加速度之间的函数关系。从实验得出，当径向加速度达到某一临界限值时才会出现旋转效应。     

一种分数间隔解相关修正判决反馈盲均衡算法研究

以消除多径效应对传输信号的影响、提高信号传输的效率为背景,在介绍基于CMA算法的判决反馈盲均衡算法(DFE算法)的基础上,提出了改进的分数间隔判决反馈盲均衡算法。通过实验仿真结果的分析表明,改进方法在收敛速度、剩余误差等方面取得明显改善,具有一定的实际应用价值。     

高空模拟试车台主被动引射方案数值研究

采用二维轴对称雷诺平均方程和Spalart-Allmaras湍流模型,对一大面积比火箭发动机高空模拟试车台在不同引射方案下发动机启动至稳定运行过程中不同室压下的流场结构进行了数值模拟.空间上采用二阶迎风格式进行耦合求解,时间上采用显式Runge-Kutta方法进行迭代推进.结果表明,采用启动段主动引射、主级段被动引射的...     

Airfoil Aeroelastic Flutter Analysis Based on Modified Leishman-Beddoes Model at Low Mach Number

Based on modified Leishman-Beddoes (L-B) state space model at low Mach number (lower than 0.3), the airfoil aeroelastic system is presented in this paper. The main modifications for L-B model include a new dynamic stall criterion and revisions of normal force and pitching moment coefficient. The bifurcation diagrams, the limit cycle oscillation (LCO) phase plane plots and the time domain response figures are applied to investigating the stall flutter bifurcation behavior of airfoil aeroelastic systems with symmetry or asymmetry. It is shown that the symmetric periodical oscillation happens after subcritical bifurcation caused by dynamic stall, and the asymmetric periodical oscillation, which is caused by the interaction of dynamic stall and static divergence, only happens in the airfoil aeroelastic system with asymmetry. Validations of the modified L-B model and the airfoil aeroelastic system are presented with the experimental airload data of NACA0012 and OA207 and experimental stall flutter data of NACA0012 respectively. Results demonstrate that the airfoil aeroelastic system presented in this paper is effective and accurate, which can be applied to the investigation of airfoil stall flutter at low Mach number.     

轮盘弹塑性盘破裂准则的建立及变厚度轮盘破裂转速预测

建立了与材料延伸率相关的轮盘弹塑性破裂准则。为了验证所提出破裂准则的正确性,采用非线性有限元对变厚度轮盘破裂试验件的破裂转速进行了预测,并与试验结果进行了对比。结果表明,二者吻合很好。     

某型涡轴发动机地面低温起动技术研究

分别从不加温直接起动、数控系统控制规律更改、加温后起动等各方面对某型全数控涡轴发动机在高寒机场的地面低温起动试验进行分析研究,最终总结出该型发动机的地面低温起动规律。结果表明：延长起动机带转时间,并对发动机进行适时加温,可使发动机低温起动成功。     

某直升机燃油增压泵性能优化

利用流体仿真技术对某直升机燃油增压泵过流部件进行优化设计,并完成了试验验证。结果表明,经过理论设计-仿真计算-理论设计循环优化后的产品,其性能明显优于原型产品:提高了泵的效率,降低了泵的消耗电流,提高产品工作稳定性。